Tandem collector assembly for overhead electrification system



J. W. RONEY Aug. 6, 1968 TANDEM COLLECTOR ASSEMBLY FOR OVERHEADELECTRIFICATION SYSTEM Original Filed Feb. 14, 1966 INVENTOR. J/v/i/ fl/Qx/f/ BY 244M M United States Patent 3,396,246 TANDEM COLLECTOR ASSEMBLYFOR OVER- HEAD ELECTRIFICATION SYSTEM John W. Roney, Los Altos, Calif.,assignor, by mesne assignments, to The Rucker Manufacturing Company,Oakland, Calif., a corporation of California Continuation of applicationSer. No. 527,287, Feb. 14, 1966. This application Jan. 2, 1968, Ser. No.695,283 17 Claims. (Cl. 191-58) ABSTRACT OF THE DISCLOSURE Thisinvention relates generally to a collector assembly for an overheadelectrification system, and, more particularly, to a tandem collectorassembly designed to operate in continuous and discontinuous systems;this tandem collector assembly forming the present invention comprisesgenerally a base member, a pair of oppositely disposed spring biasedmovable arms supported thereon, and insulated conductor shoes pivotallysupported on the arms for engaging a conductor bar to transfer currentto auxiliary equipment associated with the collector assembly.

This application is a continuation of Ser. No. 527,287,

filed Feb. 14, 1966, now abandoned.

SPECIFICATION While multi-head collector mechanisms of one sort are notnovel per se, for example, see Patent No. 3,123,191 issued to D. G.Sprigings on Mar. 3, 1964 for a Current Collector Mechanism, the needfor a highly versatile tandem collector assembly which satisfies thecompeting design principles involved in low profile current collectorsystems has long been sought. The present invention 00- alesces a numberof features to provide an insulated tandem collector assembly effectiveto conform to variations in the path of the conductor bar of an overheadelectrification system, to present a relatively low profile and tofunction in discontinuous or interrupted systems.

In addition to the foregoing, the present invention provides a saferassembly than many prior art ones. The collector shoes are fullyinsulated from the assembly body so that there is little likelihood of aworker accidently contacting an electrically hot part of the collectorhead assembly or burning himself by contacting an electrically insulatedbut heat dissipating surface. This insulation feature also avoids heatfatiguing the various biasing means. Thus, the biasing means will notlose their resiliency.

Yet another advantage of the present invention is obtained by usingtorsional springs to bias the arms against each other. This allows eachshoe to maintain an equal contact pressure against the conductor bar.Since the arms work against each other and not against a base memberhaving no direct connection to the tensioning system, the elfectivenessof the biasing means is not degraded.

Broadly speaking, the tandem collector assembly of the present inventioncomprises a pair of arms mounted in tandem for movement primarily in afirst plane and to a lesser extent in planes transverse thereto, acollector head and shoe assembly mounted in the free end of each of thearms for rotation primarily in the first plane and to a lesser extent inplanes transverse thereto, first resilient means associated with thearms urging the free ends thereof toward each other and toward theconductor bar with which the collector assembly cooperates, and secondresilient means connected between the heads to urge the collector headand shoe assemblies to remain in alignment.

3,396,246 Patented Aug. 6, 1968 ice More particularly, the presentinvention combines a base or yoke member, a pair of channel shapedtandem arms pivotally connected to the yoke for movement with at leasttwo degrees of freedom, an insulated collector head mounting a shoeattached to the outermost ends of each of the arms for movement with atleast two degrees of freedom, torsion spring means cooperating with thearms to bias the arms towards each other and towards the conductor barof an overhead electrification system when the assembly is in operativeposition, coil spring means associated with the collector heads to urgethem to remain in a common plane, and means connecting the shoes toelectrical equipment remote therefrom for the transfer of current fromthe conductor bar to the remote equipment.

These and other objects, features and advantages of the presentinvention may be more fully understood when the following detaileddescription is read with reference to the drawings, in which:

FIG. 1 is a plan view of the tandem arm collector assembly forming thepresent invention;

FIG. 2 is a cross-section view taken along line 2-2 of FIG. 1 to moreclearly illustrate the manner in which the arms are pivoted on the yoke;

FIG. 3 is a side view of the tandem arm collector assembly forming thepresent invention; and

FIG. 4 is an end view of the assembly of FIG. 3 with a portion brokenaway to more clearly show the relationship of the parts thereof.

The tandem collector assembly forming the present invention broadlyincludes a base or yoke member 10, a pair of elongate, generally channelshaped, tandem arms 12 and 14 pivotally connected on the base member byan axle or pin 15, and a pair of collector head and shoe assemblies 16,18 pivotally mounted on the opposite outer ends of the arms 12 and 14 bypins 22 and 24, respectively. The arms 12 and 14 are biased towards eachother by a pair of torsion springs 26 and 28 which are mounted side byside and concentric of the axle 15 and have opposite ends cooperatingwith respective middle portions of the arms 12 and 14. An aligning, lowk coil spring 30 is connected between the interior ends of the collectorhead assemblies 16 and 18 to urge the head and shoe assemblies 16 and 18to maintain a generally common alignment.

Looking more particularly to the construction and operation of thevarious parts of the present invention, the base or yoke member 10comprises a generally U-shaped body 32 having a pair of upstanding legs33 and 34 which are apertured to receive pin 15 which can be in the formof a rivet or similar axle fixed between the legs 33 and 34. A stop bar36 is held in fixed relation to the bite of the U-shaped member 32 by anAllen set screw 37 and extends outwardly through each leg 33 and 34 byway of rectangular apertures 41 and 42.

The two arms 12 and 14 are identical in construction and can beinterchangeably connected to form the tandem collector assembly. Thearms 12 and 14 are generally elongate members having a broad U-shapedchannel portion 46 at one end, generally having approximately the samewidth or bite as the bite of the U-shaped body 32, and a reducedU-shaped channel 47 at its other end. The reduced channel has one sidecommon to the outer U- shaped channel 46. The inner leg 49 thereof actsin cooperation with the common leg 48 to provide the channel 47 whichhas a width approximately, but a little less than, one-half of the widthof the bite of the U of body 32 of the base 10.

The reduction channel sections 47 have a pair of elongate slots 52formed in each side of the legs 48 and 49 of the channel section topivotally mount the legs in opposite opposed relation on the axle 15.The elongate slots 52 permit the arms 12 and 14 to be moved in variousplanes which intersect the path of the conductor bar or longitudinalaxis thereof, denominated as 50. This relative transverse ornon-longitudinal movement of the two arms 12 and 14 and theircooperating collector head and shoe assemblies 16 and 18 permit thistandem collector assembly to track on a conductor bar even though theconductor bar is not in a straight line or even in a simple plane.

The two torsion springs 26 and 23 are mounted concentrically on the axleor pin Within the respective reduced channel sections 47 (illustratedmost clearly in FIG. 1). The torsion springs 26 and 28 are symmetricallymounted therein whereby the outermost free end 260 and 28a,respectively, of each torsion spring are connected toward theintermediate part of the arm 14 by being projected through a pair oftransversely spaced-apart apertures 56 and 57. Thereafter, the ends ofthe members 26a and 28a are bent at right angles to engage the undersideof the arm 14 to maintain them in place on the arm 14. The opposite freeends 26b and 28b of the respective torsion springs 26 and 28 areconnected in a similar manner toward the intermediate part of arm 12 byway of transversely spaced-apart apertures 58 and 59. With thisarrangement, the torsional springs 26 and 28 act evenly to urge the armsagainst each other towards a generally closed position or, what is thesame thing, towards the conductor bar as shown by dotted line in FIG. 3.Moreover, the symmetrical connection eliminates any cocking moment onthe axle 15.

Without any restraint, the arms 12 and 14 would move towards each otherpushing the collector head and shoe assemblies 16 and 18 upward andtowards each other (with respect to orientation of the assembly as shownin FIG. 3). However, the stop bar 36 cooperating with the yoke 10, actsto provide a position stop for the upward movement of the arms 12 and 14(illustrated most clearly in FIG. 3). The size of the stop bar 36 isselected whereby the ends of the reduced channel sections 47 contact theupper surface 61 thereof to prevent further upward movement of the arms12 and 14 and their cooperating collector head and shoe assemblies 16and 18. It will be apparent that by the selection of this stop bar 36and its spaced-apart relation to the pin and axle 15, it is possible topre-select the particular stop location for the arms 12 and 14.

The collector head and shoe assemblies 16 and 18 are pivotally mountedon the pins 22 and 24 affixed between the spaced-apart legs of the outerU-shaped channel members 46 to permit rotation of the collector head andshoe assemblies 16 and 18 in a plane generally in line with thelongitudinal plane of movement of the assembly along a conductor bar.

The collector head and shoe assemblies 16 and 18 each include aninsulated collector head 64 and a conductive shoe of copper or similarmaterial 66 aflixed therein. The insulated collector heads 64 has atransverse slot 67 formed therethrough for pivotally supportingcollector heads 64 on the pins 22 and 24. There is also provided anaperture 68 in the interior end of each or" the collector heads 64.

A low k, relatively weak, coil spring is connected between the interiorsides of the opposed collector heads 64 at the aperture 68 and acts tourge the collector heads 64 and their cooperating conductive shoes 66 tobe maintained in a common plane lying generally along the longitudinaldirection of movement of the collector assembly along the conductor bar.

It should be noted that the strength of the coil spring 30 is quitesmall. It contributes very little to the contact pressure exered by thecollector head and shoe assemblies 16 and 18 against the conductor barshown in dotted line in FIG. 3. The contact pressure for the collectorshoes 66 against the conductor bar is rovided by the torsional springs26 and 28, while the low k coil spring 30 acts merely to urge the edgesof the shoe 66 to maintain an in-line position. This is particularlynecessary when the collector assembly is used in a discontinuous circuitfor the collector assembly must be guided back onto a conductor barafter temporary interruption. The low k spring performs this necessaryfunction but leaves the shoe and head assemblies free to adjust withlittle or no binding.

The conductive shoes 66 are formed with a pair of generallylongitudinally oriented grooves 69 on each side, as particularly shownin the cut-away illustration of FIG. 4, which are engaged by theinsulated collector head 64 to maintain the conductive shoe 66 in situ.An electric Wire receptacle 71 is provided in cooperation with a screwmember 72 at one end of the conductive shoe 66 to permit connection ofan electrical lead 73 to the conductor shoe 66 for connection at aremote point to auxiliary equipment to which current is to be suppliedby the overhead electrification system.

In the exemplary embodiment of the present invention, the silhouette ofthe overall tandem collector assembly is maintained quite low to provideapproximately 1 /2 inch travel or variation between the normal movementof the collector head and shoe assemblies 16 and 18 with respect to theconductor bar. The torsion springs 26 and 28 are selected atapproximately sixteen pound-inches per turn and designed with a 2 /2inch fulcrum between the point of rotation for the arms at axle 15 andthe point of attachment for the collector head and shoe assemblies 16and 18. With these proportions and a quarter bias turn of the torsionsprings, the upward force of the conductor shoes against the conductorbar is approximately three and one-half pounds per shoe. In thisparticular type of low silhouette overhead electrification system, it isdesirable to keep the collector contact pressure between 2 /z5 poundsper shoe. Substantially none of the three and one-half pounds ofcollector head pressure need be provided by the low strength coil spring30 which acts primarily to keep the two collector head and shoeassemblies 16 and 18 in alignment.

From the foregoing description, it can be seen that the present tandemcollector assembly permits the collector head and shoe assemblies 16 and18 to move with at least two degrees of freedom with respect to the arms12 and 14. In turn, the arms 12 and 14 can move primarily in the planeof the conductor bar, but to a more limited extent in planes transversethereto to provide the necessary degrees of freedom for the overallmovement of the arm. The overall assembly can adapt to variations in thedirection and sense of the conductor bar, and adapt the assembly for usein both continuous and discontinuous systems which are tailored tospecific requirements of a given industrial plant. It makes nodifference whether the systems are vertical or horizontal, or use insideand/or outside curves. The exemplary embodiment can be utilized on a onefoot horizontal curve or a vertical curve of six feet or less. Thesegive extreme versatility to the overall collector assembly.

As noted heretofore, the conductive shoes 66 are insulated from the restof the system so that there is no danger of electric current flowingthrough the arms 12 and 14 and the associated yoke 10, which parts aworkman or other personnel in the plant might very well touch duringoperation and use. The insualted shoes also prevent heat from theconductor bar and conductive shoes from reaching any of the biasingmembers which would materially shorten their useful lives.

While this invention has been described with respect to a specificembodiment, it should be apparent to those skilled in the art thatvarious changes may be envisaged without departing from the scope of thepresent invention. For this reason, the invention should be limited onlyto the extent of the specific recitations in the claims.

I claim:

1. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system comprising:

(a) a pair of arms mounted in tandem for movement primarily in a firstplane which is coincident with the plane of the conductor bar when thecollector assembly is operatively cooperating therewith, and to a lesserextent in planes transverse thereto;

(b) a collector head assembly mounted in the free end of each of saidarms for rotation primarily in said first plane and to a lesser extentin planes transverse thereto;

(c) first resilient means associated with said arms to urge the freeends thereof toward each other and towards the conductor bar with whichthe collector assembly cooperates; and

(d) second resilient means connected between said collector headassemblies to urge the conductive shoes thereof to remain in alignment.

2. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 1 wherein thecollector heads are formed of an insulating material to electricallyisolate the conductive shoes from the other parts of said tandemcollector assembly.

3. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 1 wherein thelimited transverse movement of the arms and collector head assemblies isobtained by forming slots in said arms and said collector heads topivotally support them for primary movement in said first plane.

4. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system comprising:

(a) ayoke;

(b) tandem disposed arms pivotally connected to said yoke at one set oftheir ends so that each can move with two degrees of freedom;

(c) a collector head mounting a shoe attached to the outermost end ofeach of said arms so that it can move with two degrees of freedom;

(d) spring means cooperating with the yoke and the arms to bias the armstowards each other and towards the conductor bar of an overheadelectrification system when the collector assembly is operativelycooperating therewith;

(d) alignment means associated with said collector heads to urge saidheads to remain in a common lane; and

(f) means connecting said tandem shoes to electrical equipment remotetherefrom for the transfer of current from the conductor bar to theauxiliary equipment.

5. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 4 wherein saidcollector heads are formed of an insulating material to insulate theyoke and arms of the tandem assembly from the collector shoes.

6. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 4, andincluding stop means associated with the yoke to prevent the arms frommoving towards each other beyond a predetermined separation.

7. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 4 wherein themeans pivotally connecting the arms to the yoke include slots formed inthe arms so that the collector heads and shoes can move in the twodegrees of freedom system including the plane of the conductor bar andplanes transverse thereto, and said collector heads are slotted topermit them to move with the same two degrees of freedom with respect tothe ends of said arms.

8. A tandem collector assembly adapted to engage the conductor bar of anoverhead electrification system in accordance with claim 7 wherein thespring means is a pair of torsion springs symmetrically mounted aboutthe axle pivotally supporting the arms on the yoke, and said alignmentmeans is a relatively small coil spring which does not contributematerially to the contact pressure of the collector head.

9. A tandem arm collector assembly adapted to engage the conductor barof an overhead electrification system comprising, in combination,

(a) a base member having an axle mounted thereon;

(b) first and second arms having slots formed in one set of their endsto mount said arms on said axle for movement generally in a plane commonto the conductor bar but with some movement in plans transverse thereto;

(c) said arms mounted so that they extend outwardly from opposite sidesof said base member generally in said common plane;

((1) insulated collector heads with conductive shoes mounted thereonhaving slots formed therethrough to permit their pivotal attachment tothe other ends of said arms for rotation generally in said common planebut with some movement in planes transverse thereto;

(e) a pair of torsion springs concentrically mounted in side-by-siderelation on said axle, the opposite ends of each spring connected torespective ones of said first and second arms to urge said arms andtheir pivotally mounted collector heads toward the conductor bar of theoverhead electrification system and away from said base member;

(i) stop means on said base member to limit the rotational movement ofsaid arms with respect to said base member;

g) a low k coil spring connected between the interior ends of saidcollector heads to urge the edges of said conductive shoes to remain ina common plane; and

(h) terminal means associated with said conductive shoes to permitcurrent from the conductor bar to be transferred through said shoes toauxiliary equipment remote therefrom.

10. A tandem arm collector assembly adapted to engage the conductor barof an overhead electrification system comprising, in combination,

(a) a U-shaped yoke supporting an axle between the outer parts of thelegs thereof in a plane transverse to the longitudinal axis of theconductor bar when the assembly is operatively associated therewith;

(b) first and second tandem arms, each one of said arms having one endformed in the shape of a channel approximately the same width as thebite of the U-shaped yoke and the other end formed in the shape of areduced channel with :a bite extending to a little less than half thewidth of the bite of said U-shaped yoke;

(c) elongate slots formed in the legs of each of said reduced channelsto mount said arms in side-by-side relation on said axle with the largeU-shaped ends of said arms extending outwardly in opposite directionsfrom said yoke for rotation generally in the longitudinal plane of saidconductor bar but with sufficient play to allow the arms to move inother planes to accommodate variations in the lie of the conductor bar;

(d) pins transversely mounted on the outer ends of said arms between thelegs of the outwardly disposed channels thereof;

(e) insulated collector heads having removable conductive shoes mountedlongitudinally therein formed with transverse slots therethrough so asto mount said head and shoe assemblies on the pins of their respectivearms whereby said heads are rotatable in said longitudinal plane and tolimited extent in other planes to said longitudinal plane so that saidcollector heads can traverse inside and outside curved conductor bars;

(f) a pair of torsion springs rotatably mounted on the axle of saidyoke, one interior of each of said reduced channels, the transverseoutermost arms of each of said torsion springs held in transverseSpaced-apart relation toward the intermediate part of one of said armsand the transverse inwardly disposed arms of each of said torsionsprings held in transverse spaced-apart relation toward the intermediatepart of the other of said arms so as to urge said arms toward each otherand toward the conductor bar of the overhead electrification system withwhich it cooperates;

(g) a stop bar transversely mounted through the legs of said U-shapedyork adjacent the bite thereof to cooperate with said one ends of saidarms to limit the movement of said arms with respect to said yoke; and

(h) a low k coil spring connected between the inwardly disposed ends ofsaid insulated collector heads so as to urge said heads and theirassociated shoes to stay in alignment to facilitate use of the collectorhead assembly in discontinuous electrification systems.

11. A tandem current collector comprising (a) a base;

(b) first and second elongated collector arms independently pivotalabout the same axis on the base and extending generally in oppositedirections from the base;

(c) first and second collector heads respectively mounted on the outerends of the first and second collector arms; and

(d) at least one torsional spring wound about said axis and coupled atits opposite ends respectively to the first and second collector armsfor spring loading said arms against one another about said axis.

12. The apparatus of claim 11 further characterized by the fact that acoil spring is connected directly between the near ends of the collectorheads to urge them into coplanar alignment, said coil spring being weakcompared to the torsional spring so as to contribute a minimum toloading the collector arms about the axis.

13. The apparatus of claim 11 further characterized by the facts that:

(a) the base is in the form of a yoke having a pair of spaced apartlegs, with a pivot pin extending between the legs of the yoke;

(h) each collector arm has its outer end formed in the shape of a largechannel of about the same width as the yoke, and has its inner endformed in the shape of a reduced channel olfset to one side of the largechannel and of about one-half the width of the yoke;

(c) the inner ends of both collector arms have aligned openings in thelegs of the reduced channels for receiving the pivot pin; and

(d) the collector arms are mounted on the pivot pin, with the reducedchannels disposed in side-by-side relationship in the yoke and with thelarge channels disposed in alignment with the yoke, so that the reducedchannel of each arm is aligned with the large channel of the oppositearm.

14. The apparatus of claim 13 further characterized by the fact thatfirst and second torsional springs are wound about the pivot pinrespectively Within the confines of the reduced channels of the firstand second collector arms, each torsional spring having one endconnected to its associated collector arm and having its other endconnected to the aligned portion of the large channel of the oppositecollector arm.

15. The apparatus of claim 13 further characterized by the fact that thealigned openings in the legs of the reduced channel portion of eachcollector arm are elongate slots which provide a restricted degree offreedom for the collector arms in planes parallel to the pivot pin.

16. The apparatus of claim 15 further characterized by the fact that thecollector heads are mounted pivotal on pins caught in elongate slots inthe legs of the large channels of the respective collector arms near theouter ends thereof.

17. The apparatus of claim 13 further characterized by the fact that anadjustable stop bar is mounted below the pivot pin in the yoke forengagement with the bight formed by the extreme inner ends of thecollector arms, in order to limit the pivotal position of the collectorarms about the pivot pin.

References Cited

